Sihe Steel
Sihe Steel
Explore our engineering capabilities across welded tubes, sheets, plates, and customized coiled capillaries.
A technical guide on composition, weld seam integrity, and mechanical resilience under corrosive parameters.
Stainless steel welded tubes manufactured from grade TP316 (UNS S31600) represent the benchmark for industrial corrosion resistance and structural endurance. Incorporating molybdenum (2.0% to 3.0%), TP316 provides a highly robust defense against localized pitting corrosion, chloride attack, and stress-cracking compared to conventional chromium-nickel alloys like TP304.
For critical processing units, engineers often choose between TP316 and its low-carbon counterpart, TP316L (UNS S31603). The control of carbon below 0.03% in TP316L prevents chromium carbide precipitation at the grain boundaries during welding, maintaining maximum corrosion resistance in as-welded assemblies.
Design Advantage: By choosing TP316/316L welded tubing from advanced Chinese factories utilizing modern weld-seam processing, industries achieve properties comparable to seamless tubes at a significant reduction in capital expenditure.
The alloy composition is governed strictly by manufacturing standards including ASTM A249, ASTM A269, and ASTM A312. Below is the typical metallurgical breakdown comparing TP316, TP316L, and key alloys:
| Element (%) | TP316 (UNS S31600) | TP316L (UNS S31603) | Duplex 2205 (UNS S32205) | TP304 (UNS S30400) |
|---|---|---|---|---|
| Chromium (Cr) | 16.0 - 18.0 | 16.0 - 18.0 | 22.0 - 23.0 | 18.0 - 20.0 |
| Nickel (Ni) | 10.0 - 14.0 | 10.0 - 14.0 | 4.5 - 6.5 | 8.0 - 11.0 |
| Molybdenum (Mo) | 2.0 - 3.0 | 2.0 - 3.0 | 3.0 - 3.5 | - |
| Carbon (C) max | 0.08 | 0.030 | 0.030 | 0.08 |
| Nitrogen (N) | - | - | 0.14 - 0.20 | - |
A view into our high-precision online bright annealing, cold drawing, and quality testing lines.
Utilizing high-purity hydrogen gas shields to heat-treat welded tubes above 1040°C online, retaining a scaling-free, mirror-like finish without the need for acid pickling.
Physical reduction and cold working of the weld bead area to align mechanical grains, removing weld profile inequalities and eliminating structural variations in the pipe wall.
Integrated electromagnetic Eddy Current and hydrostatic testing to identify defects, wall-thinning, micro-cracks, and internal weld porosity across the production run.
Our factory specializes in customizing TP316 welded and capillary tubes to exact dimensional tolerances. With an outer diameter range extending from 0.125 inches (3.175 mm) up to 1 inch (25.4 mm), and wall thicknesses up to 0.165 inches (3 mm), we serve standard commercial requirements and unique engineering specifications alike.
We manufacture super-long coiled tubes up to 32,800 feet (10,000 meters) in continuous lengths. These long coils eliminate the need for orbital socket welds in oil, gas, and marine umbilical pipelines, reducing potential leak paths and improving system safety.
All TP316 tubes undergo strict quality inspection protocols: flaring tests, bending, hardness checks, tensile testing, and high-pressure air tightness validation prior to packaging.
Where high corrosion resistance, precision flow, and material longevity are required.
Maintains thermal transfer efficiency in steam boilers, condenser arrays, and shell-and-tube heat exchangers, resisting scale formation and thermal fatigue.
Transports acids, chlorides, and highly acidic process media under high temperatures. Ideal for sulfur recovery units and oil distillation towers.
Delivers high-purity fluid transfer with low internal roughness (Ra values optimized through bright annealing), preventing biological buildup.
Serves as evaporator coils and condenser loops, handling refrigerants and heat exchange fluids with minimal thermal expansion leakage risks.
How Liaocheng Sihe delivers high-volume production with reliable quality controls.
Operating out of Liaocheng, China's stainless steel manufacturing center, Liaocheng Sihe Stainless Steel Material LTD integrates raw material sourcing with advanced tube cold drawing and automated welding technologies. Our close ties to premium domestic smelting hubs ensure consistent supply and reliable chemical properties.
By managing both tube forming and thermal processes in-house, we can handle dynamic orders while keeping production costs down. We maintain strict control over parameters like dimensional roundness and surface quality, enabling us to deliver reliable products to over 30 countries.
Logistics & Quality Control: Located near major shipping corridors and ports like Qingdao, our logistic networks ensure safe packaging and timely international transport of custom reels, spools, and straight tube lengths.
Our products are engineered and tested in accordance with international standards.
Detailed answers from our engineering and metallurgy teams regarding specifications, compliance, and orders.
Explore our wider range of stainless steel and capillary products, fabricated to global engineering standards.
2205 duplex stainless steel containing austenitic and ferritic phases for high mechanical strength.
1/2 inch coiled options engineered specifically for hydraulic instrumentation control lines.
High-temperature oxidation resistant grades fabricated for chemical processing furnaces.
